package julian

import (
	"fmt"
	"testing"
	"time"
)

func TestMonthLength(t *testing.T) {
	var tests = []struct {
		y    int
		m    time.Month
		want int
	}{
		{2001, time.January, 31},
		{2001, time.February, 28},
		{2000, time.February, 29},
		{2001, time.March, 31},
		{2001, time.April, 30},
		{2001, time.May, 31},
		{2001, time.June, 30},
		{2001, time.July, 31},
		{2001, time.August, 31},
		{2001, time.September, 30},
		{2001, time.October, 31},
		{2001, time.November, 30},
		{2001, time.December, 31},
	}

	for _, tt := range tests {
		testname := fmt.Sprintf("%v, %d", tt.m, tt.y)
		t.Run(testname, func(t *testing.T) {
			ans := monthLength(tt.y, tt.m)
			if ans != tt.want {
				t.Errorf("got %d, want %d", ans, tt.want)
			}
		})
	}
}

func TestJDateDiff(t *testing.T) {
	var tests = []struct {
		d    JDate
		days int
		want JDate
	}{
		{JDate{2001, time.January, 20}, 5, JDate{2001, time.January, 25}},
		{JDate{2001, time.February, 28}, 5, JDate{2001, time.March, 5}},
		{JDate{2004, time.February, 28}, 5, JDate{2004, time.March, 4}},
	}

	for _, tt := range tests {
		testname := fmt.Sprintf("%v, %d", tt.d, tt.days)
		t.Run(testname, func(t *testing.T) {
			ans := jDateDiff(tt.d, tt.days)
			if ans != tt.want {
				t.Errorf("got %d, want %d", ans, tt.want)
			}
		})
	}
}

func TestNextMonth(t *testing.T) {
	ans1, ans2 := nextMonth(2000, time.December)
	if ans1 != 2001 || ans2 != time.January {
		t.Errorf("nextMonth(2000, time.December) = %d, %v; want 2001, time.January", ans1, ans2)
	}
}

func TestJDateToGDate(t *testing.T) {
	var tests = []struct {
		d    JDate
		want GDate
	}{
		{JDate{100, time.February, 29}, GDate{100, time.February, 27}},
		{JDate{100, time.March, 1}, GDate{100, time.February, 28}},
		{JDate{100, time.March, 2}, GDate{100, time.March, 1}},
		{JDate{200, time.February, 28}, GDate{200, time.February, 27}},
		{JDate{200, time.February, 29}, GDate{200, time.February, 28}},
		{JDate{200, time.March, 1}, GDate{200, time.March, 1}},
		{JDate{300, time.February, 28}, GDate{300, time.February, 28}},
		{JDate{300, time.February, 29}, GDate{300, time.March, 1}},
		{JDate{300, time.March, 1}, GDate{300, time.March, 2}},
		{JDate{500, time.February, 28}, GDate{500, time.March, 1}},
		{JDate{500, time.February, 29}, GDate{500, time.March, 2}},
		{JDate{500, time.March, 1}, GDate{500, time.March, 3}},
		{JDate{600, time.February, 28}, GDate{600, time.March, 2}},
		{JDate{600, time.February, 29}, GDate{600, time.March, 3}},
		{JDate{600, time.March, 1}, GDate{600, time.March, 4}},
		{JDate{700, time.February, 28}, GDate{700, time.March, 3}},
		{JDate{700, time.February, 29}, GDate{700, time.March, 4}},
		{JDate{700, time.March, 1}, GDate{700, time.March, 5}},
		{JDate{900, time.February, 28}, GDate{900, time.March, 4}},
		{JDate{900, time.February, 29}, GDate{900, time.March, 5}},
		{JDate{900, time.March, 1}, GDate{900, time.March, 6}},
		{JDate{1000, time.February, 28}, GDate{1000, time.March, 5}},
		{JDate{1000, time.February, 29}, GDate{1000, time.March, 6}},
		{JDate{1000, time.March, 1}, GDate{1000, time.March, 7}},
		{JDate{1100, time.February, 28}, GDate{1100, time.March, 6}},
		{JDate{1100, time.February, 29}, GDate{1100, time.March, 7}},
		{JDate{1100, time.March, 1}, GDate{1100, time.March, 8}},
		{JDate{1300, time.February, 28}, GDate{1300, time.March, 7}},
		{JDate{1300, time.February, 29}, GDate{1300, time.March, 8}},
		{JDate{1300, time.March, 1}, GDate{1300, time.March, 9}},
		{JDate{1400, time.February, 28}, GDate{1400, time.March, 8}},
		{JDate{1400, time.February, 29}, GDate{1400, time.March, 9}},
		{JDate{1400, time.March, 1}, GDate{1400, time.March, 10}},
		{JDate{1500, time.February, 28}, GDate{1500, time.March, 9}},
		{JDate{1500, time.February, 29}, GDate{1500, time.March, 10}},
		{JDate{1500, time.March, 1}, GDate{1500, time.March, 11}},
		{JDate{1582, time.October, 4}, GDate{1582, time.October, 14}},
		{JDate{1582, time.October, 5}, GDate{1582, time.October, 15}},
		{JDate{1582, time.October, 6}, GDate{1582, time.October, 16}},
		{JDate{1700, time.February, 18}, GDate{1700, time.February, 28}},
		{JDate{1700, time.February, 19}, GDate{1700, time.March, 1}},
		{JDate{1700, time.February, 28}, GDate{1700, time.March, 10}},
		{JDate{1700, time.February, 29}, GDate{1700, time.March, 11}},
		{JDate{1700, time.March, 1}, GDate{1700, time.March, 12}},
		{JDate{1800, time.February, 17}, GDate{1800, time.February, 28}},
		{JDate{1800, time.February, 18}, GDate{1800, time.March, 1}},
		{JDate{1800, time.February, 28}, GDate{1800, time.March, 11}},
		{JDate{1800, time.February, 29}, GDate{1800, time.March, 12}},
		{JDate{1800, time.March, 1}, GDate{1800, time.March, 13}},
		{JDate{1900, time.February, 16}, GDate{1900, time.February, 28}},
		{JDate{1900, time.February, 17}, GDate{1900, time.March, 1}},
		{JDate{1900, time.February, 28}, GDate{1900, time.March, 12}},
		{JDate{1900, time.February, 29}, GDate{1900, time.March, 13}},
		{JDate{1900, time.March, 1}, GDate{1900, time.March, 14}},
		{JDate{2100, time.February, 15}, GDate{2100, time.February, 28}},
		{JDate{2100, time.February, 16}, GDate{2100, time.March, 1}},
		{JDate{2100, time.February, 28}, GDate{2100, time.March, 13}},
		{JDate{2100, time.February, 29}, GDate{2100, time.March, 14}},
	}

	for _, tt := range tests {
		testname := fmt.Sprintf("%v, %v", tt.d, tt.want)
		t.Run(testname, func(t *testing.T) {
			ans := JDateToGDate(tt.d)
			if ans != tt.want {
				t.Errorf("got %v, want %v", ans, tt.want)
			}
		})
	}
}

func TestGDateToJDate(t *testing.T) {
	var tests = []struct {
		gd   GDate
		want JDate
	}{
		{GDate{100, time.February, 27}, JDate{100, time.February, 29}},
		{GDate{100, time.February, 28}, JDate{100, time.March, 1}},
		{GDate{100, time.March, 1}, JDate{100, time.March, 2}},
		{GDate{200, time.February, 27}, JDate{200, time.February, 28}},
		{GDate{200, time.February, 28}, JDate{200, time.February, 29}},
		{GDate{200, time.March, 1}, JDate{200, time.March, 1}},
		{GDate{300, time.February, 28}, JDate{300, time.February, 28}},
		{GDate{300, time.March, 1}, JDate{300, time.February, 29}},
		{GDate{300, time.March, 2}, JDate{300, time.March, 1}},
		{GDate{500, time.March, 1}, JDate{500, time.February, 28}},
		{GDate{500, time.March, 2}, JDate{500, time.February, 29}},
		{GDate{500, time.March, 3}, JDate{500, time.March, 1}},
		{GDate{600, time.March, 2}, JDate{600, time.February, 28}},
		{GDate{600, time.March, 3}, JDate{600, time.February, 29}},
		{GDate{600, time.March, 4}, JDate{600, time.March, 1}},
		{GDate{700, time.March, 3}, JDate{700, time.February, 28}},
		{GDate{700, time.March, 4}, JDate{700, time.February, 29}},
		{GDate{700, time.March, 5}, JDate{700, time.March, 1}},
		{GDate{900, time.March, 4}, JDate{900, time.February, 28}},
		{GDate{900, time.March, 5}, JDate{900, time.February, 29}},
		{GDate{900, time.March, 6}, JDate{900, time.March, 1}},
		{GDate{1000, time.March, 5}, JDate{1000, time.February, 28}},
		{GDate{1000, time.March, 6}, JDate{1000, time.February, 29}},
		{GDate{1000, time.March, 7}, JDate{1000, time.March, 1}},
		{GDate{1100, time.March, 6}, JDate{1100, time.February, 28}},
		{GDate{1100, time.March, 7}, JDate{1100, time.February, 29}},
		{GDate{1100, time.March, 8}, JDate{1100, time.March, 1}},
		{GDate{1300, time.March, 7}, JDate{1300, time.February, 28}},
		{GDate{1300, time.March, 8}, JDate{1300, time.February, 29}},
		{GDate{1300, time.March, 9}, JDate{1300, time.March, 1}},
		{GDate{1400, time.March, 8}, JDate{1400, time.February, 28}},
		{GDate{1400, time.March, 9}, JDate{1400, time.February, 29}},
		{GDate{1400, time.March, 10}, JDate{1400, time.March, 1}},
		{GDate{1500, time.March, 9}, JDate{1500, time.February, 28}},
		{GDate{1500, time.March, 10}, JDate{1500, time.February, 29}},
		{GDate{1500, time.March, 11}, JDate{1500, time.March, 1}},
		{GDate{1582, time.October, 14}, JDate{1582, time.October, 4}},
		{GDate{1582, time.October, 15}, JDate{1582, time.October, 5}},
		{GDate{1582, time.October, 16}, JDate{1582, time.October, 6}},
		{GDate{1700, time.February, 28}, JDate{1700, time.February, 18}},
		{GDate{1700, time.March, 1}, JDate{1700, time.February, 19}},
		{GDate{1700, time.March, 10}, JDate{1700, time.February, 28}},
		{GDate{1700, time.March, 11}, JDate{1700, time.February, 29}},
		{GDate{1700, time.March, 12}, JDate{1700, time.March, 1}},
		{GDate{1800, time.February, 28}, JDate{1800, time.February, 17}},
		{GDate{1800, time.March, 1}, JDate{1800, time.February, 18}},
		{GDate{1800, time.March, 11}, JDate{1800, time.February, 28}},
		{GDate{1800, time.March, 12}, JDate{1800, time.February, 29}},
		{GDate{1800, time.March, 13}, JDate{1800, time.March, 1}},
		{GDate{1900, time.February, 28}, JDate{1900, time.February, 16}},
		{GDate{1900, time.March, 1}, JDate{1900, time.February, 17}},
		{GDate{1900, time.March, 12}, JDate{1900, time.February, 28}},
		{GDate{1900, time.March, 13}, JDate{1900, time.February, 29}},
		{GDate{1900, time.March, 14}, JDate{1900, time.March, 1}},
		{GDate{2100, time.February, 28}, JDate{2100, time.February, 15}},
		{GDate{2100, time.March, 1}, JDate{2100, time.February, 16}},
		{GDate{2100, time.March, 13}, JDate{2100, time.February, 28}},
		{GDate{2100, time.March, 14}, JDate{2100, time.February, 29}},
	}

	for _, tt := range tests {
		testname := fmt.Sprintf("%v, %v", tt.gd, tt.want)
		t.Run(testname, func(t *testing.T) {
			ans := GDateToJDate(tt.gd)
			if ans != tt.want {
				t.Errorf("got %v, want %v", ans, tt.want)
			}
		})
	}
}